Relevance and Reliability of Outdoor SO2 Monitoring in Low-Income Countries Using Low-Cost Sensors

Abstract

In the Western world, the SO2 concentration in ambient air dropped to low levels, but some emission sources (e.g., merchant ships) and some regions (e.g., low-income countries) still emit substantial amounts of SO2. At those locations, SO2 monitoring is critical. However, low-income countries do not have much access to expensive reference instruments. Low-cost gas sensors might be an alternative, but it is unclear how reliable such measurements are. To evaluate the performance of the low-cost alternative, the same SO2 gas sensor has been subjected to three different calibration methods: (1) low-cost calibration performed in the tropical climate of Cuba; (2) high-end calibration performed in Belgium; (3) a field calibration at an air quality measuring station in Belgium. The first two methods showed similar trends, suggesting that the gas sensor can be calibrated with a low-cost method. The field calibration was hampered by the low SO2 concentrations. For the monitoring campaign in Cienfuegos, Cuba, the low-cost SO2 sensor calibrated by the low-cost method appeared to be sufficiently reliable. The reliability of the sensor increases with the increase in SO2 concentration, so it can be used in Cuba instead of Belgium.

APTES functionalization in SBA-15: the effect on SO2 capture and detection applications

“…Although the focus has been directed towards SO 2 capture methods, accurate detection is also essential for assessing air quality and addressing this pollutant gas's environmental and health impact. 13 Various detection methods are currently employed, each with its strengths. In this scenario, the fluorescence detection method has emerged as a prominent approach due to its exceptional sensitivity and selectivity for SO 2 .…”